Fluids (e.g., oil, water, gas) exist in a variety of materials, including geological formations. It is often useful to determine the properties of a fluid, or of multiple fluids, such as viscosity, diffusivity, and fluid type. Fluid identification models based on nuclear magnetic resonance (NMR) use NMR measurements to acquire fluid signature data from a selected material in the form of echo trains containing information about relaxation times, which in turn can be used to identify fluids and determine fluid properties. Interested readers may refer to U.S. Pat. No. 6,512,371 (incorporated herein by reference in its entirety) describing how NMR data can be acquired.
To determine fluid properties, echo trains can be used to estimate NMR T1 and T2 relaxation time distributions. Unfortunately, total porosity values derived separately from T1 and T2 relaxation time distributions may not agree, giving rise to interpretation uncertainties with respect to the fluid type data.